Browser "quirks" mode breaks the application

[philcunliffe]

Based on my investigation on an issue similar to #109 , if the browser is in quirks mode (document.compatMode is "BackCompat") the application completely breaks. This state is most often caused by the lack of a tag but given that this application is embeddable it's likely that the application will be rendered in quirks mode.

When using the bounding-box tool the horizontal crosshair is gone and when attempting to draw a box the Y coordinates generated are somehow very low negative numbers (things like -10000).

[seveibar]

Hey @philcunliffe, can you give the steps to reproduce?

[philcunliffe]

It should happen if you embed the application on any page without a declaration

You can check to see if the browsers in quirks mode by checking document.compatMode https://developer.mozilla.org/en-US/docs/Web/API/Document/compatMode